Improved kiln for anne aliwg glass



@sind dtjijirr.

`THOMAS Lower, or PITTSBURG," PENNSYLVANIA.

Letters Patent No. 100,424, dated March 1, 1870.

IMPROVED KILN FOR ANNEALIG- AC|II'.|ASS.

The Schedule "referred to in these Letters Patent and malrxing` part ofthe same.

I, THOMAS Lower, of Pittsburg, in the county of Allegheny, and State ofPennsylvania, have invented a new and useful ImprovementinAnnealing-Kilns or Furnaces, used for the purpose of flattening andanealingcylinders of glass, preparatory to their being `out intowindow-panes.

H cretofore the tablet orfspreading-plates .of such kilns have been madeof fire-clay, or highlyirefractory sandstone, upon the surface of whichthe cylinder: ofr glass is placed, lying with its `split uppermost. Thedarne passing over it, causes it to open and fall back intoa wavy sheet,the operator rubbing down the wavyness into a fiat surface by meansof ablock of hard wood upon the endof an iron rod. But as thespreading-stones or tablets cannot be kept very even or smooth, owing totheir friable nature, and as `they absorb and retain more heat than isabsolutely necessary for the accomplishment of the desired object, thesoft glass molds itself tothe unequal surface, and adheresto and takesup such particles of the stone or clay as cause a serious defectin theotherwise perfect sheet.

Nature and Objects of the I iwen'tz'on.

My invention consists in makingthe flattening-tablets of metal,eachi'orxning a shallow rectangular box, perfectly tight, andcirculating therein steam, hot water, hot air, or other elastic iiu'ids,as will tend to keep the upper surface of the tablets at such atemperature asis best suited to the attening process, and yet p reventthe adhesion of the glass, and by which an even clean surface can be atall times maintained.

Description. of the Accompanying Drawings. `Figure 1 represents atransverse vertical section of my improved annealing andflattening-kiln. y Figure 2, a transverse section ori a horizontalplane, just above the tablets.

p Gcmiwral Dscription. This kiln consists of exterior and interiorwalls, S, the interveningv space being a circular arched vault.

In this vault is a cast-iron frame, G, supported by a hollow verticalshaft, B, resting on a pivot, A, and capable of being turned round by acrank on the ontside, connect-ed toa shaft and wheels inside.

This frame C in the kiln carries the flattening-tablets D, which, inthis case, are shallow, air-tight` mctallic boxes, perfectly flat ontheir upper side.

From the bottom and interior of each ot' these hollow tablets extend twopipes, one of which, H, enters the bottom of atank, V, around thecentral shaft B, while the other communicates with the interior of saidshaft, which is open at the top.

Water is conveyed to the tank V through a suitable supply-pipelN,provided with necessary cocks.

The kiln, on being heated to the proper degree of temperature, is workedin the followig manner:

The cylinder of glass is placedv in proper position on one ofthetablets. The frame C is then turned until the cylinder is broughtopposite the working-hole, through which it is flat-tened in theordinary way.

During this operation, the water in the tank V is passing down the pipeH into the tablet, tending to.

keep it sufficiently cool to prevent the glass from sticking thereto.

As the water is soon brought to a boiling point, the steam generated isallowed to pass out of the tablet, through the exit-pipe L, into theshaft, and from thence into the atmosphere, or the pipes may be soarranged as that thesteam and circulatingwater may be returned to thetank and worked over and over, which 4 perhaps wouldbe better vthanallowing it to escape.

, Although my invention is described .and shown as applied to a circularkiln, provided with a rotating frame and tablets, still IdoV not intendto limit myself to that peculiar mechanical construction ot' furnace orkiln, as it is applicable to all kinds of kilns used for annealing andflattening of glass,`regardless of their shape or kind.

C Zaim.

' I claim the hollow tablets, with the inlet and out-Y Vitnesses:

Josmn W. Enns, JAMES M. TAYLOR.

